Dental spraying apparatus



Jan. 22, 1935. R. H. CAMPBELL DENTAL SPRAYING APPARATUS Filed May 18, 1933 INVE NTO R Patented Jan. 22, 1935' UNITED STATES PATENT OFFICE Application M3! 18, 1933, Serial No. 671,762 In Great Britain October 13, 1032 1 Claim.

This invention relates to dental spraying apparatus of the kind comprising a vessel for containing a medicament, dentifrice, or other solution (hereinafter referred to as the solution),'a

5 removable head screwed onto the upper end of the said vessel, a capsule (of the kind commonly known under the registered trade-mark Sparklet) containing gas under pressure such, for example, as carbon dioxide and carried in a holder screwed onto the said head, and a hollow piercer in the saidhead adapted to pierce the said capsule, upon screwing up the said holder, to liberate the saidgas which then passes through passages in the head into the said vessel and acts to force the said solution up a siphon tube,

controlled by a valve, and then through an outlet tube having a spraying jet, or nozzle, at its outer end, the said valve being actuated by abell-crank lever in opposition to a spring which :0 acts to close the said valve. The vessel is provided with a filling orifice through which the solution is poured. In order to prevent liability of the vessel bursting when the solution is subjected to the pressure of the gas it is essential :5 that the quantity of solution charged into the said vessel should be such that it does not extend beyond a predetermined level in the said vessel, so that there is suin'cient space above the solution to allow for the expansion of the gas liberlo ated from the capsule without subjecting the vessel to undue internal pressure and to allow for the said space to contain high pressure gas for completely atomizing the solution passing from the siphon tube when the apparatus is in [5 use. Hitherto the charging of the vessel with a predetermined quantity of solution has been effected by first emptying the said vessel of any solution that may be in it and then pouring therein a previously measured quantity of solution, but In no provision has, however, .been made in the apparatus which will ensure that only the predetermined quantity of solution for which the vessel is intended is contained therein.

In bottles, siphons, or other vessels in which 15 capsules of compressed or liquefied gas are employed for saturating liquid contained in the said vessels it has been proposed to deaden the shock caused by the liberation of the gas within the vessel by providing a tube closed at its upper end which is inserted into the vessel after the latter has been filled with liquid. When the gas is liberated it forces part of the liquid up into the tube so that the air trapped therein is compressed and serves as a buffer to deaden the shock.

situated at any desired part of the upper por- This invention has for its object to provide an 0 improved construction oi spraying apparatus of the aforesaid kind wherein liability of the vessel containing the solution being subjected to undue internal pressure by the expansion of liberated gas therein is eliminated, or considerably reduced. 5

According to this invention the vessel for containing the solution to be sprayed is provided with a filling tube which is secured to and projects into the said vessel in such manner that during the charging thereof with solution, poured through the said filling tube, an air-lock space is automatically created between the opposed walls of the said filling tube and the said vessel, the capacity of the said space being sufficient to allow for the expansion of liberated gas without subjecting the said vessel to undue internal pressure. The inner orifice of the filling tube through which the solution is poured, is at a predetermined distance from the upper end of the said vessel so that when the level of the solution in '20 the said vessel reaches and closes the said orifice the air-lock is automatically created in the said vessel in the space above the said orifice and prevents any solution entering the said space although solution may be continued to be poured into the said filling tube, and ensures that the solution in the said vessel does not exceed a predetermined quantity. The air-lock space is of such capacity, as to allow for the expansion of liberated gas without subjecting the vessel to undue internal pressure, and to-contain high pressure gas which acts to completely atomize the solution passing from the siphon tube when the apparatus is in use. The filling tube may be 85 tion of the vessel and any suitable means may be provided for closing the outer orifice of the said tube but it is preferred removably to secure the said tube in the neck of the said vessel.

I will particularly describe this invention with reference to the accompanying drawing which illustrates in vertical section a dental spraying apparatus embodying the invention.

The apparatus comprises a vessel 1, for containing the solution, having an internally screwthreaded neck 2 into the lower part of which the upper screw-threaded end of a filling tube 8 is screwed and in the upper part of which a screwthreaded bush .4 on the underside of the head 5 is screwed, a fluid-tight joint being effected by 50 interposing between the said neck and the head a ring 6- of ebonite, or other suitable material. The filling tube 3 is of such length that when screwed into position in the neck of the vessel 1 its inner orifice is at the level at which the 56 requisite quantity of solution in the said vessel shall reach, so that when the solution poured into the vessel reaches this level the space 7 in the portion of the vessel above the said level is airlocked and over-charging oi the vessel is thereby prevented. To charge the vessel 1 with solution the head 5 is removed from the screw-threaded neck 2 of the vessel 1, the solution is then poured into the open neck and passes, through the filling tube 3, into the said vessel until it commences to rise up the said tube thereby indicating that the vessel is charged to the desired amount whereupon the supply is stopped and the head is replaced on the neck of the said vessel.

The head 5 is provided with an externally screw-threaded socket 8 onto which is screwed a holder 9 for a capsule 10, of the type commonly known under the registered trade-mark Sparklet", containing gas under pressure, such, for example as carbon di-oxide. The socket 8 is provided with a hollow piercer 11 which upon screwing up of the holder 9 penetrates the closure of the capsule 10 and liberates the gas therein which passes into a chamber 12 in the socket 8, from thence through passages 13 and 14 in the head 5, and into the filling tube 3 where it subjects the solution in the vessel 1 to pressure. The inlet orifice of the passage 13 may be controlled by any suitable non-returnvalve, such for example as that shewn and described in the specification of Letters Patent No. 8742 A. D. 1905.

The solution in the vessel 1 is forced, by the pressure of the liberated gas, up a siphon tube 15 in communication with a'passage 16 in the head 5 and having its outer orifice controlled by a valve in a valve chamber 17 formed in the said head. The siphon tube 15 passes through the filling tube 3 and is secured, by any suitable means, to the head 5 so that it is removable therewith. This may be effected, as shewn in the drawing, by securing an externally screwthreaded and centrally bored bush 18 to the outlet end of the siphon tube 15 and screwing the said bush into an enlarged and internally screwthreaded portion of the passage 16 in the head 5. A filter 19 may be secured to the inlet end of the siphon tube 15 to prevent any particles, or other foreign matter, entering the said tube. When the apparatus is in operation excess of liberated gas contained in the air-lock 7 enters the filling tube 3, passes through a hole, or holes, 15a in the upper portion of the siphon tube 15, and-mixes with the stream of gas saturated solution passing up the said-siphon tube thereby completely atomizing the said solution. 1

The valve controlling the outlet of the passage 16 in'the head 5 consists of a piece of resilient material 20, such, for example, as rubber, secured to the underside of a plunger 21 the stem 22 of which is connected to one arm 23 of a bell-crank actuating lever, pivoted at 24 to the head 5, the other arm 25 of the said lever being bent downwardly in convenient position to be operated by the manipulator whilst holding the apparatus. Leakage of fluid past the valve is prevented by a washer 26 of resilient material, such as rubber,

pressed onto the upper side of the plunger 21 by a spring 27 surrounding the stem 22 of the said plunger and interposed between a metal washer 28 and a cap 29, through which the upper end of the said stem projects, the said cap being screwed into the upper end of the valve chamber 17 and constituting the closure thereof. The spring 27 also acts to return the valve onto its seating after actuation.

Leading from the lower portion of the valve chamber 17 is 'an outlet passage '30 in communication with an outlet tube 31 having its outer portion bent as'shewn and a spraying jet, or nozzle, 32 at its extreme end, so that when the valve is raised, by actuation of the bell-crank lever 23,

-25, the solution under pressure passes from the passage 16 into the passage and then into the said outlet tube 31 and discharges through the spraying jet, or nozzle. Secured to the inner end of the outlet tube 31 is a tapered spigot 33 which is rotatably and resiliently held in a correspondingly shaped soc lret 34, formed in a bush 35 on the head 5, by a spring 36 interposed between the outer end of the said spigot and the inner side of an elongated hollow coupling nut 37 screwed onto the said bush. The interposition of the spring 36 between the aforesaid parts ensures a fiuid tight joint, under normal working conditions, between the spigot 33 and the socket 34 but will allow of slight outward longitudinal movement of the outlet tube 31 to permit the said tube to be easily turned when it is required to adjust the directional inclination of the outer bent portion thereof. In order to facilitate turning of the outlet tube 31 a milled edge collar 38, or its equivalent, may be secured thereto, and in order to prevent the liability of solution, or saliva, from the patients mouth being projected onto the apparatus, or the manipulator, a guard 39, of any suitable shape, may be secured to the said tube at a suitable distance from the spraying jet, or nozzle, thereon.

It is desirable, in order to facilitate the ready manipulation of the apparatus, that the arm 25 of the valve actuating lever be in the same vertical plane as the outlet tube 31 and in order to container carrying a capsule of compressed gas,

means for establishing communication between lel with the wall of the container and having an aperture therein through which the outlet projects.

ROBERT HUNTER CAMPBELL. 

